#include<iostream>
#include"Sales_item.h"
int main()
{
	Sales_item total;
	if(std::cin >> total)
	{
		Sales_item trans;
		while(std::cin >> trans)
		{
			if(total.isbn() == trans.isbn())
				total += trans; 
			else {
				std::cout << total << std::endl;
				total = trans;
			}
		}
	std::cout << total << std::endl;
	} else {
		std::cerr << "No data?!" << std::endl;
		return -1;
	}
	return 0;
} 
